On the coordination of motor output during visual flight control of flies

Zanker, Johannes M.; Egelhaaf, Martin; Warzecha, Anne-Kathrin

doi:10.1007/bf00215860

Cited by 17 publications

(25 citation statements)

References 33 publications

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“…During most flight bouts the head motion in flight generally consists of small, rapid movements, as well as large head motions that typically accompany large turns. As expected from prior studies (Hengstenberg, 1991a;Zanker et al, 1991;van Hateren and Schilstra, 1999), we observed a strong coordination between head yaw and wing motion, i.e. the head turned in the same direction of an intended turn.…”

Section: What Does the Discrepancy Between Head-fixed And Head-free Rsupporting

confidence: 90%

Visual motion speed determines a behavioral switch from forward flight to expansion avoidance inDrosophila

Reiser

Dickinson

2012

Journal of Experimental Biology

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SUMMARYAs an animal translates through the world, its eyes will experience a radiating pattern of optic flow in which there is a focus of expansion directly in front and a focus of contraction behind. For flying fruit flies, recent experiments indicate that flies actively steer away from patterns of expansion. Whereas such a reflex makes sense for avoiding obstacles, it presents a paradox of sorts because an insect could not navigate stably through a visual scene unless it tolerated flight towards a focus of expansion during episodes of forward translation. One possible solution to this paradox is that a flyʼs behavior might change such that it steers away from strong expansion, but actively steers towards weak expansion. In this study, we use a tethered flight arena to investigate the influence of stimulus strength on the magnitude and direction of turning responses to visual expansion in flies. These experiments indicate that the expansion-avoidance behavior is speed dependent. At slower speeds of expansion, flies exhibit an attraction to the focus of expansion, whereas the behavior transforms to expansion avoidance at higher speeds. Openloop experiments indicate that this inversion of the expansion-avoidance response depends on whether or not the head is fixed to the thorax. The inversion of the expansion-avoidance response with stimulus strength has a clear manifestation under closedloop conditions. Flies will actively orient towards a focus of expansion at low temporal frequency but steer away from it at high temporal frequency. The change in the response with temporal frequency does not require motion stimuli directly in front or behind the fly. Animals in which the stimulus was presented within 120deg sectors on each side consistently steered towards expansion at low temporal frequency and steered towards contraction at high temporal frequency. A simple model based on an array of Hassenstein-Reichardt type elementary movement detectors suggests that the inversion of the expansion-avoidance reflex can explain the spatial distribution of straight flight segments and collision-avoidance saccades when flies fly freely within an open circular arena.

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Section: What Does the Discrepancy Between Head-fixed And Head-free Rsupporting

confidence: 90%

Visual motion speed determines a behavioral switch from forward flight to expansion avoidance inDrosophila

Reiser

Dickinson

2012

Journal of Experimental Biology

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“…Previous studies on flight control in tethered flies suggest that hind leg steering during optomotor yaw response reinforces wingflapping-induced moments by strongly increasing (decreasing) the leg extension angle on the inner (outer) side of an intended yaw turn (Zanker, 1988a(Zanker, , 1991. The author proposed that this synergy increases the fly's agility and manoeuvrability, which may, in turn, increase survival rate during aerial predation by dragonflies (Combes et al, 2012).…”

Section: Coherence Of Steeringmentioning

confidence: 98%

“…The vast majority of previous studies on the significance of body appendages for force and moment support in actively flying animals were conducted in insects such as the small fruit fly (Götz et al, 1979;Zanker, 1988b), the house fly (Zanker et al, 1991), orchid bees (Combes and Dudley, 2009) and moths (Cheng et al, 2011;Hedrick and Daniel, 2006). Early studies on various freely flying insect species suggested that leg steering and shifting the insect's centre of body mass support wing-induced moments during manoeuvring (Ellington, 1984d).…”

Section: Introductionmentioning

confidence: 99%

“…Early studies on various freely flying insect species suggested that leg steering and shifting the insect's centre of body mass support wing-induced moments during manoeuvring (Ellington, 1984d). This hypothesis was further investigated under visual stimulation mimicking yaw turns, during which tethered flying flies bend hind legs and abdomen in the horizontal to the inner side of the intended turn (Götz et al, 1979;Zanker, 1988a,b;Zanker et al, 1991). Visual stimulation mimicking body pitching, by contrast, leads to bending of the abdomen in the vertical, with upward bending during upward motion of the visual pattern (Dyhr et al, 2013;Frye, 2001;Hinterwirth and Daniel, 2010).…”

Section: Introductionmentioning

confidence: 99%

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Body appendages fine-tune posture and moments in freely manoeuvring fruit flies

Berthé

Lehmann

2015

Journal of Experimental Biology

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The precise control of body posture by turning moments is key to elevated locomotor performance in flying animals. Although elevated moments for body stabilization are typically produced by wing aerodynamics, animals also steer using drag on body appendages, shifting their centre of body mass, and changing moments of inertia caused by active alterations in body shape. To estimate the instantaneous contribution of each of these components for posture control in an insect, we three-dimensionally reconstructed body posture and movements of body appendages in freely manoeuvring fruit flies (Drosophila melanogaster) by high-speed video and experimentally scored drag coefficients of legs and body trunk at low Reynolds number. The results show that the sum of leg-and abdomen-induced yaw moments dominates wing-induced moments during 17% of total flight time but is, on average, 7.2-times (roll, 3.4-times) smaller during manoeuvring. Our data reject a previous hypothesis on synergistic moment support, indicating that drag on body appendages and massshift inhibit rather than support turning moments produced by the wings. Numerical modelling further shows that hind leg extension alters the moments of inertia around the three main body axes of the animal by not more than 6% during manoeuvring, which is significantly less than previously reported for other insects. In sum, yaw, pitch and roll steering by body appendages probably fine-tune turning behaviour and body posture, without providing a significant advantage for posture stability and moment support. Motion control of appendages might thus be part of the insect's trimming reflexes, which reduce imbalances in moment generation caused by unilateral wing damage and abnormal asymmetries of the flight apparatus.

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“…First of all, it is necessary to exclude the possibility that the relatively slow dynamics of the behaviourally generated motion traces is the consequence of the lowpass properties of the flight simulator . Since in another behavioural context (object detection and fixation), that was also analysed using the flight simulator, much faster responses are generated by the fly than during optomotor course control (Egelhaaf 1987;Zanker et al 1991;Kimmerle et al 1997), the dynamics of the flight simulator are not the main determinant of the dynamics of the behaviourally generated optomotor responses. In addition, increasing or decreasing the cut-off frequency of the lowpass filter in Encoding Visual Motion in Real-Time 265 the flight simulator by a factor of two does not change the dynamics of the optomotor responses in any obvious manner .…”

mentioning

confidence: 99%